1N4729A

Overview

The onsemi 1N4729A is a Zener diode housed in a DO-41 glass case, designed for voltage regulation and reference applications. It features a nominal Zener voltage of 3.6 V with a tolerance of ±5%, measured at a test current of 69 mA. The device supports a maximum power dissipation of 1.0 W at lead temperatures up to 50°C, requiring a derating factor of 6.67 mW/°C above this threshold. It operates within a junction and storage temperature range of -65°C to +200°C. Key electrical characteristics include a maximum Zener impedance of 10 Ω at the test current and a leakage current limit of 1 μA at 1 V reverse voltage.

Feature Summary

• Utilizes a DO-41 glass encapsulation for robust environmental protection and thermal stability.
• Provides precise voltage regulation with a tight 5% tolerance band around the nominal Zener voltage.
• Capable of handling high surge currents through non-repetitive peak reverse current ratings.

Applications

• Voltage reference circuits requiring stable low-voltage benchmarks.
• Overvoltage protection stages in power supply inputs.
• Clamping applications in signal conditioning paths.

Procurement Notes

Verify the specific ordering suffix against the manufacturer's datasheet to ensure correct packaging and marking configurations. Confirm that the component meets all absolute maximum ratings for your operating environment, particularly regarding power dissipation and thermal derating requirements above 50°C. Ensure compatibility with the intended PCB footprint for the DO-41 package.

Selection Notes

Select this component when a stable 3.6 V reference is required with moderate power handling capabilities. Consider the 5% tolerance if tighter precision is not critical for the application. Evaluate the thermal management strategy to ensure the junction temperature remains within limits during continuous operation, accounting for the specified derating curve.

Part Context

This part belongs to the 1N4728A–1N4758A series of Zener diodes manufactured by onsemi. The series offers a wide range of nominal voltages from 3.3 V to 56 V, all sharing similar physical dimensions and general electrical characteristics. The 1N4729A specifically targets the lower end of this voltage spectrum, providing a compact solution for low-voltage regulation tasks.

Replacement Considerations

Cross-reference with other manufacturers' 1N4729A equivalents to verify pinout compatibility and electrical parameter alignment. Ensure substitute parts meet or exceed the 1.0 W power dissipation rating and the -65°C to +200°C operating temperature range specified in the original datasheet.